4c4b1996b5
The work_item cancels that occur when a QP is destroyed can elicit the
following trace:
workqueue: WQ_MEM_RECLAIM ipoib_wq:ipoib_cm_tx_reap [ib_ipoib] is flushing !WQ_MEM_RECLAIM hfi0_0:_hfi1_do_send [hfi1]
WARNING: CPU: 7 PID: 1403 at kernel/workqueue.c:2486 check_flush_dependency+0xb1/0x100
Call Trace:
__flush_work.isra.29+0x8c/0x1a0
? __switch_to_asm+0x40/0x70
__cancel_work_timer+0x103/0x190
? schedule+0x32/0x80
iowait_cancel_work+0x15/0x30 [hfi1]
rvt_reset_qp+0x1f8/0x3e0 [rdmavt]
rvt_destroy_qp+0x65/0x1f0 [rdmavt]
? _cond_resched+0x15/0x30
ib_destroy_qp+0xe9/0x230 [ib_core]
ipoib_cm_tx_reap+0x21c/0x560 [ib_ipoib]
process_one_work+0x171/0x370
worker_thread+0x49/0x3f0
kthread+0xf8/0x130
? max_active_store+0x80/0x80
? kthread_bind+0x10/0x10
ret_from_fork+0x35/0x40
Since QP destruction frees memory, hfi1_wq should have the WQ_MEM_RECLAIM.
The hfi1_wq does not allocate memory with GFP_KERNEL or otherwise become
entangled with memory reclaim, so this flag is appropriate.
Fixes: 0a226edd203f ("staging/rdma/hfi1: Use parallel workqueue for SDMA engines")
Reviewed-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
Signed-off-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.